Simon Willison’s Weblog

Items tagged xss, security, html

Filters: xss × security × html ×


Reducing XSS by way of Automatic Context-Aware Escaping in Template Systems (via) The Google Online Security Blog reminds us that simply HTML-escaping everything isn’t enough—the type of escaping needed depends on the current markup context, for example variables inside JavaScript blocks should be escaped differently. Google’s open source Ctemplate library uses an HTML parser to keep track of the current context and apply the correct escaping function automatically. # 14th April 2009, 9:26 am

Coding Horror: Protecting Your Cookies: HttpOnly. Jeff Atwood discovers the hard way that writing an HTML sanitizer is significantly harder than you would think. HttpOnly cookies aren’t the solution though: they’re potentially useful as part of a defense in depth strategy, but fundamentally if you have an XSS hole you’re going to get 0wned, HttpOnly cookies or not. Auto-escape everything on output and be extremely cautious with things like HTML sanitizers. # 29th August 2008, 2:01 am